期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：6
页码：2312-2317
DOI：10.1073/pnas.1815961116
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Adaptive immune response is part of the dynamic changes that accompany motoneuron loss in amyotrophic lateral sclerosis (ALS). CD4+ T cells that regulate a protective immunity during the neurodegenerative process have received the most attention. CD8+ T cells are also observed in the spinal cord of patients and ALS mice although their contribution to the disease still remains elusive. Here, we found that activated CD8+ T lymphocytes infiltrate the central nervous system (CNS) of a mouse model of ALS at the symptomatic stage. Selective ablation of CD8+ T cells in mice expressing the ALS-associated superoxide dismutase-1 (SOD1)G93A mutant decreased spinal motoneuron loss. Using motoneuron-CD8+ T cell coculture systems, we found that mutant SOD1-expressing CD8+ T lymphocytes selectively kill motoneurons. This cytotoxicity activity requires the recognition of the peptide-MHC-I complex (where MHC-I represents major histocompatibility complex class I). Measurement of interaction strength by atomic force microscopy-based single-cell force spectroscopy demonstrated a specific MHC-I-dependent interaction between motoneuron and SOD1 G93A CD8+ T cells. Activated mutant SOD1 CD8+ T cells produce interferon-γ, which elicits the expression of the MHC-I complex in motoneurons and exerts their cytotoxic function through Fas and granzyme pathways. In addition, analysis of the clonal diversity of CD8+ T cells in the periphery and CNS of ALS mice identified an antigen-restricted repertoire of their T cell receptor in the CNS. Our results suggest that self-directed immune response takes place during the course of the disease, contributing to the selective elimination of a subset of motoneurons in ALS.
关键词：amyotrophic lateral sclerosis ; neuroimmunity ; cytotoxic T lymphocytes ; motoneuron ; major histocompatibility complex I
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